Welding Fluxes

WeldingFluxes are made of granulized inorganic or metal materials playing the roles such as conductivity of arc length, formation of slag coatings and melt deoxygenation in the submerged welding. They also play the role of electrode cover in the manual process. The physical appearance of the welding flux is dependent to the elements present within the material. In addition, the size and dimensions of the fluxes are very important. There is no general welding flux that can be used for every metals and gaps, and thus, the selection of the welding flux must be done according to the application. The maximum ampere consumption is achieved during the application of welding flux in the process. Welding fluxes are found in three types: acidic, neutral and basic. Another classification is two types of pre-melt and agglomerated welding fluxes. Pre-melt welding fluxes are obtained through melting of grinded raw materials. The melted product is then cooled, grinded and screened in order to achieve desired dimensions. The strength and density of these pellets are high and this prevents their pulverization during handling and storage. Pre-melted welding fluxes are resistant against oxygen and hydrogen diffusion and hydrogen cracking and subsequently can be used for open areas, unroofed structures and humid environments.

Flux OP 121TT

OP 121TT is a fully basic agglomerated submerged-arc welding flux that is widely used for the welding of structural and fine grained low alloy steels requiring high integrity welds with low temperature impact and CTOD fracture toughness properties.

Flux OP 139

OP 139 is an agglomerated aluminate basic flux which has been designed for use with the high deposition rate submerged arc processes, such as twin-wire, tandem or multi-wire. It can be used for both longitudinal and circumferential seams. Even at high speeds the wetting at the toe of the weld remains smooth and straight. The slag detaches very easily in long pieces even in fillet welds. OP 139 can be used for all structural, pipe and boiler steels and for fine grained steels. There is a slight donation of manganese and silicon. In multilayer welds OP 139 is used in conjunction with OE-S2 and in DSAW with OE-S2Mo. Damp flux should be re-dried at 300-350°C. Grain size according to EN 760: 2-20.

Flux OP 122

OP 122 is an agglomerated fluoride-basic type flux for joint welding general structural steels, pressure vessel steels, pipe steels and fine-grain steels. OP 122 has a high current-carrying capacity and is therefore also suited to welding fillets with a large throat thickness in steel constructions. The flux has an easily detachable slag. As the bulk density is low, so is the consumption rate. OP 122 can be welded on DC+ pole and AC at up to 1200 A. The special production method ensures that the flux has low moisture pick-up and the weld metal a low hydrogen content. Damp flux should be re-dried at 300-350°C. Grain size according to EN 760: 2-20.

Flux OP 76

OP 76 is a special agglomerated, fluoride-basic type flux for welding stainless and heat-resistant steels when used in conjunction with wires according to AWS A5.9. In terms of weld metal C content, the behaviour of OP 76 can be described as neutral, thus if suitable wires are used, ELC quality steels may be welded. In terms of silicon and manganese, the metallurgical behaviour is neutral, i.e. there is neither pick-up nor burn-out. Manganese burn-out only occurs when wires with a high manganese content are used. OP 76 is intended for joint welding large cross-sec

On the other hand, agglomerated welding fluxes are produced by mixing of fully grinded raw materials. Adhesives such as sodium and potassium silicates are added to form the paste and then pyrolyzed at 600-800 degrees centigrade. Since this temperature range is below the reaction temperature of the materials, anti-oxygen and ferroalloys can be used. Although the production cost of agglomerated welding fluxes are high, the ultimate usage of these fluxes in the process is low due to their low volumetric density.